甲嘧磺隆等3种除草剂对云南黄馨、金钟扦插苗成苗及生长的影响

Effect of Three Herbicides on the Seedling and Growth of Cutting Seedlings of Jasminum mesnyi and Forsythia viridissima

阔叶杂草是苗圃中重要的危害性杂草,然而控制苗圃阔叶杂草的有效化学方法却很少,主要原因是能防除阔叶草的除草剂往往对苗木不安全或缺少对其安全性研究。选择甲嘧磺隆、乙氧氟草醚和扑草净3种杀草谱较广的除草剂,通过2015年田间小区试验,研究不同用量下这3种除草剂对苗圃常见苗木云南黄馨、金钟扦插苗成苗、发芽、生根、株高等因素的影响。结果显示:用药时雨水、土壤湿度可严重影响植物生长状况,雨水多、湿度大,则发根、出叶少;用药时间影响药剂效应,扦插前用药,药剂影响大于扦插后用药,这可能是扦插前、扦插后苗在遇药时的叶芽状态及水分不同所造成的。研究还发现,药剂对苗木成苗无不良影响,7.5 g a.i./hm^275%甲嘧磺隆WDG处理对苗木出叶、株高无影响;而在生根方面,在药后30 d,只有对照的71.1%,用药后100 d,与对照相当,乙氧氟草醚144、288 g a.i./hm^2,扑草净450、900 g a.i./hm^24个处理的结果与甲嘧磺隆7.5 g a.i./hm^2处理相同;对于甲嘧磺隆15 g a.i./hm^2处理,在前期对苗木出叶、生根都有较大影响,3个月后影响逐渐减少甚至消失;甲嘧磺隆22.5 g a.i./hm^2处理对苗木出叶、生根、株高的抑制可持续3个月以上。

Broad leaf weeds are important damaging species in forest nurseries with only a few herbicides available for their selective control on forest seedlings. Field experiments were conducted in 2015 to evaluate the influence of broad - spectrum herbicides including sulfometuron - methyl, oxyfluorfen and prometryn at different doses on the seedling, sprouting, rooting and plant height of Jasminum mesnyi Hance and Forsythia viridissima Lindl cutting seedlings. Growth of the two cutting seedlings was seriously influenced by rainfall and soil moisture, excessive rain and high soil moisture decrease sprouting and rooting. Herbicide damage to seedlings depended on plant growth stage ; herbicide damage to seedlings applied before cutting was more critical than when applied after cutting, the reason may due to the leaf bud station and moisture situation when use the herbicide. None of the treatment affected seedling survival rate. Sulfometuron 75% WDG at 1.5 g a. i. /hm^2 did not affect sprout or seedling height,but was harmful to root development decreasing it to 71% of the control at 30 days after treatment although the plants fully recovered by 100 days after treatment. Oxyfluorfen 24 % EC at 144 and 288 g a. i. /hm^2 and prometryn 40% WP at 450 and 900 g a. i. /hm^2 had similar effects as sulfometuron - methyl5% WDG at 7. 5 g a. i. /hm^2. Sulfometuron - methyl 75% WDG at 15 g a. i./hm^2 reduced both the amountof sprouts and roots 30 days after application but the affection disappeared 70 days latter. The damage causedby sulfometuron - methyl 75% WDG at 22. 5 g a. i. /hm^2 to leafing,rooting and plant height persisted as long as 3 months after treatment.